add basic metrics collection logic

src/exchange/taler-exchange-httpd_auditors.c

@@ -216,6 +216,7 @@ TEH_handler_auditors (
     return MHD_YES;   /* failure */
   ret = TEH_DB_run_transaction (connection,
                                 "add auditor denom sig",
+                                TEH_MT_OTHER,
                                 &res,
                                 &add_auditor_denom_sig,
                                 &awc);

src/exchange/taler-exchange-httpd_db.c

@@ -24,6 +24,7 @@
 #include <gnunet/gnunet_json_lib.h>
 #include "taler_json_lib.h"
 #include "taler_mhd_lib.h"
+#include "taler-exchange-httpd_db.h"
 #include "taler-exchange-httpd_responses.h"
 
 
@@ -113,25 +114,10 @@ TEH_make_coin_known (const struct TALER_CoinPublicInfo *coin,
 }
 
 
-/**
- * Run a database transaction for @a connection.
- * Starts a transaction and calls @a cb.  Upon success,
- * attempts to commit the transaction.  Upon soft failures,
- * retries @a cb a few times.  Upon hard or persistent soft
- * errors, generates an error message for @a connection.
- *
- * @param connection MHD connection to run @a cb for, can be NULL
- * @param name name of the transaction (for debugging)
- * @param[out] mhd_ret set to MHD response code, if transaction failed;
- *             NULL if we are not running with a @a connection and thus
- *             must not queue MHD replies
- * @param cb callback implementing transaction logic
- * @param cb_cls closure for @a cb, must be read-only!
- * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
- */
 enum GNUNET_GenericReturnValue
 TEH_DB_run_transaction (struct MHD_Connection *connection,
                         const char *name,
+                        enum TEH_MetricType mt,
                         MHD_RESULT *mhd_ret,
                         TEH_DB_TransactionCallback cb,
                         void *cb_cls)
@@ -149,6 +135,8 @@ TEH_DB_run_transaction (struct MHD_Connection *connection,
                                              NULL);
     return GNUNET_SYSERR;
   }
+  GNUNET_assert (mt < TEH_MT_COUNT);
+  TEH_METRICS_num_requests[mt]++;
   for (unsigned int retries = 0;
        retries < MAX_TRANSACTION_COMMIT_RETRIES;
        retries++)
@@ -190,6 +178,7 @@ TEH_DB_run_transaction (struct MHD_Connection *connection,
                     (-1 == (int) *mhd_ret) );
     if (0 <= qs)
       return GNUNET_OK;
+    TEH_METRICS_num_conflict[mt]++;
   }
   TALER_LOG_ERROR ("Transaction `%s' commit failed %u times\n",
                    name,

src/exchange/taler-exchange-httpd_db.h

@@ -23,6 +23,7 @@
 
 #include <microhttpd.h>
 #include "taler_exchangedb_plugin.h"
+#include "taler-exchange-httpd_metrics.h"
 #include <gnunet/gnunet_mhd_compat.h>
 
 
@@ -69,6 +70,7 @@ typedef enum GNUNET_DB_QueryStatus
  *
  * @param connection MHD connection to run @a cb for, can be NULL
  * @param name name of the transaction (for debugging)
+ * @param mt type of the requests, for metric generation
  * @param[out] mhd_ret set to MHD response code, if transaction failed (returned #GNUNET_SYSERR);
  *             NULL if we are not running with a @a connection and thus
  *             must not queue MHD replies
@@ -79,6 +81,7 @@ typedef enum GNUNET_DB_QueryStatus
 enum GNUNET_GenericReturnValue
 TEH_DB_run_transaction (struct MHD_Connection *connection,
                         const char *name,
+                        enum TEH_MetricType mt,
                         MHD_RESULT *mhd_ret,
                         TEH_DB_TransactionCallback cb,
                         void *cb_cls);

src/exchange/taler-exchange-httpd_deposit.c

@@ -497,6 +497,7 @@ TEH_handler_deposit (struct MHD_Connection *connection,
     if (GNUNET_OK !=
         TEH_DB_run_transaction (connection,
                                 "execute deposit",
+                                TEH_MT_DEPOSIT,
                                 &mhd_ret,
                                 &deposit_transaction,
                                 &dc))

src/exchange/taler-exchange-httpd_deposits_get.c

@@ -246,6 +246,7 @@ handle_track_transaction_request (
   if (GNUNET_OK !=
       TEH_DB_run_transaction (connection,
                               "handle deposits GET",
+                              TEH_MT_OTHER,
                               &mhd_ret,
                               &deposits_get_transaction,
                               &ctx))

src/exchange/taler-exchange-httpd_kyc-check.c

@@ -351,6 +351,7 @@ TEH_handler_kyc_check (
   (void) GNUNET_TIME_round_abs (&now);
   ret = TEH_DB_run_transaction (rc->connection,
                                 "kyc check",
+                                TEH_MT_OTHER,
                                 &res,
                                 &kyc_check,
                                 kyp);

src/exchange/taler-exchange-httpd_kyc-proof.c

@@ -678,6 +678,7 @@ TEH_handler_kyc_proof (
 
     ret = TEH_DB_run_transaction (kpc->rc->connection,
                                   "check proof kyc",
+                                  TEH_MT_OTHER,
                                   &res,
                                   &persist_kyc_ok,
                                   kpc);

src/exchange/taler-exchange-httpd_kyc-wallet.c

@@ -140,6 +140,7 @@ TEH_handler_kyc_wallet (
       0);
   ret = TEH_DB_run_transaction (rc->connection,
                                 "check wallet kyc",
+                                TEH_MT_OTHER,
                                 &res,
                                 &wallet_kyc_check,
                                 &krc);

src/exchange/taler-exchange-httpd_link.c

@@ -193,6 +193,7 @@ TEH_handler_link (struct TEH_RequestContext *rc,
   if (GNUNET_OK !=
       TEH_DB_run_transaction (rc->connection,
                               "run link",
+                              TEH_MT_OTHER,
                               &mhd_ret,
                               &link_transaction,
                               &ctx))

src/exchange/taler-exchange-httpd_management_auditors.c

@@ -187,6 +187,7 @@ TEH_handler_management_auditors (
 
   ret = TEH_DB_run_transaction (connection,
                                 "add auditor",
+                                TEH_MT_OTHER,
                                 &res,
                                 &add_auditor,
                                 &aac);

src/exchange/taler-exchange-httpd_management_auditors_AP_disable.c

@@ -176,6 +176,7 @@ TEH_handler_management_auditors_AP_disable (
 
   ret = TEH_DB_run_transaction (connection,
                                 "del auditor",
+                                TEH_MT_OTHER,
                                 &res,
                                 &del_auditor,
                                 &dac);

src/exchange/taler-exchange-httpd_management_post_keys.c

@@ -454,6 +454,7 @@ TEH_handler_management_post_keys (
 
     res = TEH_DB_run_transaction (connection,
                                   "add keys",
+                                  TEH_MT_OTHER,
                                   &ret,
                                   &add_keys,
                                   &akc);

src/exchange/taler-exchange-httpd_management_wire_disable.c

@@ -177,6 +177,7 @@ TEH_handler_management_post_wire_disable (
 
     res = TEH_DB_run_transaction (connection,
                                   "del wire",
+                                  TEH_MT_OTHER,
                                   &ret,
                                   &del_wire,
                                   &awc);

src/exchange/taler-exchange-httpd_management_wire_enable.c

@@ -212,6 +212,7 @@ TEH_handler_management_post_wire (
 
     res = TEH_DB_run_transaction (connection,
                                   "add wire",
+                                  TEH_MT_OTHER,
                                   &ret,
                                   &add_wire,
                                   &awc);

src/exchange/taler-exchange-httpd_management_wire_fees.c

@@ -221,6 +221,7 @@ TEH_handler_management_post_wire_fees (
 
     res = TEH_DB_run_transaction (connection,
                                   "add wire fee",
+                                  TEH_MT_OTHER,
                                   &ret,
                                   &add_fee,
                                   &afc);

src/exchange/taler-exchange-httpd_melt.c

@@ -432,6 +432,7 @@ handle_melt (struct MHD_Connection *connection,
     if (GNUNET_OK !=
         TEH_DB_run_transaction (connection,
                                 "run melt",
+                                TEH_MT_MELT,
                                 &mhd_ret,
                                 &melt_transaction,
                                 rmc))

src/exchange/taler-exchange-httpd_metrics.c

@@ -29,6 +29,11 @@
 #include <jansson.h>
 
 
+unsigned long long TEH_METRICS_num_requests[TEH_MT_COUNT];
+
+unsigned long long TEH_METRICS_num_conflict[TEH_MT_COUNT];
+
+
 MHD_RESULT
 TEH_handler_metrics (struct TEH_RequestContext *rc,
                      const char *const args[])

src/exchange/taler-exchange-httpd_metrics.h

@@ -26,6 +26,34 @@
 #include "taler-exchange-httpd.h"
 
 
+/**
+ * Request types for which we collect metrics.
+ */
+enum TEH_MetricType
+{
+  TEH_MT_OTHER = 0,
+  TEH_MT_DEPOSIT = 1,
+  TEH_MT_WITHDRAW = 2,
+  TEH_MT_MELT = 3,
+  TEH_MT_REVEAL_PRECHECK = 4,
+  TEH_MT_REVEAL = 5,
+  TEH_MT_REVEAL_PERSIST = 6,
+  TEH_MT_COUNT = 7 /* MUST BE LAST! */
+};
+
+
+/**
+ * Number of requests handled of the respective type.
+ */
+extern unsigned long long TEH_METRICS_num_requests[TEH_MT_COUNT];
+
+/**
+ * Number of serialization errors encountered when
+ * handling requests of the respective type.
+ */
+extern unsigned long long TEH_METRICS_num_conflict[TEH_MT_COUNT];
+
+
 /**
  * Handle a "/metrics" request.
  *

src/exchange/taler-exchange-httpd_recoup.c

@@ -477,6 +477,7 @@ verify_and_execute_recoup (
     if (GNUNET_OK !=
         TEH_DB_run_transaction (connection,
                                 "run recoup",
+                                TEH_MT_OTHER,
                                 &mhd_ret,
                                 &recoup_transaction,
                                 &pc))

src/exchange/taler-exchange-httpd_refreshes_reveal.c

@@ -724,6 +724,7 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
     if ( (GNUNET_OK ==
           TEH_DB_run_transaction (connection,
                                   "reveal pre-check",
+                                  TEH_MT_REVEAL_PRECHECK,
                                   &ret,
                                   &refreshes_reveal_preflight,
                                   rctx)) &&
@@ -745,6 +746,7 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
     if (GNUNET_OK !=
         TEH_DB_run_transaction (connection,
                                 "run reveal",
+                                TEH_MT_REVEAL,
                                 &ret,
                                 &refreshes_reveal_transaction,
                                 rctx))
@@ -756,6 +758,7 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
     if (GNUNET_OK ==
         TEH_DB_run_transaction (connection,
                                 "persist reveal",
+                                TEH_MT_REVEAL_PERSIST,
                                 &ret,
                                 &refreshes_reveal_persist,
                                 rctx))

src/exchange/taler-exchange-httpd_refund.c

@@ -447,6 +447,7 @@ verify_and_execute_refund (struct MHD_Connection *connection,
     if (GNUNET_OK !=
         TEH_DB_run_transaction (connection,
                                 "run refund",
+                                TEH_MT_OTHER,
                                 &mhd_ret,
                                 &refund_transaction,
                                 (void *) refund))

src/exchange/taler-exchange-httpd_reserves_get.c

@@ -315,6 +315,7 @@ TEH_handler_reserves_get (struct TEH_RequestContext *rc,
   if (GNUNET_OK !=
       TEH_DB_run_transaction (rc->connection,
                               "get reserve history",
+                              TEH_MT_OTHER,
                               &mhd_ret,
                               &reserve_history_transaction,
                               &rsc))

src/exchange/taler-exchange-httpd_transfers_get.c

@@ -515,6 +515,7 @@ TEH_handler_transfers_get (struct TEH_RequestContext *rc,
   if (GNUNET_OK !=
       TEH_DB_run_transaction (rc->connection,
                               "run transfers GET",
+                              TEH_MT_OTHER,
                               &mhd_ret,
                               &get_transfer_deposits,
                               &ctx))

src/exchange/taler-exchange-httpd_withdraw.c

@@ -521,6 +521,7 @@ TEH_handler_withdraw (struct TEH_RequestContext *rc,
     if (GNUNET_OK !=
         TEH_DB_run_transaction (rc->connection,
                                 "run withdraw",
+                                TEH_MT_WITHDRAW,
                                 &mhd_ret,
                                 &withdraw_transaction,
                                 &wc))